In the field of construction demolition, one of the principal measures of performance is the amount of scrap material that can be moved from a demolition site within a given period of time. Several factors affect this work rate.
One factor is the ability of demolition equipment to shear or pulverize the scrap metal material as efficiently as possible. Generally, it is most advantageous to use a shearing tool or pulverizer head whose operation is not interrupted by required equipment or accessory changes.
As an example of devices of the prior art, U.S. Pat. No. 4,670,983 simply provides for a mounting aperture from which a magnet might be removably hung and then removed, as needed. However, operating systems like these typically require that a magnetic lifting unit be stored or placed separate from the demolition machine, and installed in a discrete operation while the demolition tool is taken temporarily out of service. The magnetic lifting unit must then be connected to a source of power and then operated in a discrete operation in which already sheared material is moved from the position where it has been sheared into pieces or pulverized to yield smaller metal or metal-bearing pieces for removal from the demolition site.
Another factor is access and mobility within a demolition site that is typically a complex landscape of constantly changing and disorganized piles of material. It is most beneficial to be able to create and negotiate paths through the material. This requires demolition equipment to be as mobile as possible to be able to navigate the downed building material, and to be able to move and remove waste from the demolition site.
Another aspect of demolition site operation is the need to have demolition equipment that can maintain continuous operation to demolish, pick, place and remove waste material following shearing and/or pulverizing of the demolition target structure, without requiring the operator to interrupt operations to dismantle and reassemble or reconfigure the demolition machine for respective shearing and/or pulverizing steps and subsequent picking, placement and removal steps, in sequence, such as would be the case in the operation of a shearing head arm that is adapted to be used as a support for a magnet that must be hung and removed for magnetic pick, place and removal functions following shearing (as described in U.S. Pat. No. 4,670,983, hereby incorporated herein by reference). Such a device requires the operator to cease shearing operations, position the arm to accept a hung magnetic lifter, and leave the cab of the vehicle to hang the magnetic lifter and attach its power source. The operation must then be reversed following use of the magnetic lifter, in order to reinitiate shearing operations.
Such an arrangement also has the disadvantage of lacking articulation and the degrees of freedom typically associated with hydraulic arm linkages, as U.S. Pat. No. 4,670,983 calls only for the magnet to be hung from the hydraulic arm by a chain of other flexible support.
In addition, a demolition site does not lend itself to the temporary dismantling and/or storage of large portions of a demolition machine. Accordingly, it is advantageous to provide demolition equipment that can operate within limited space while being able to demolish, pick, place and remove waste material following shearing and/or pulverizing of the demolition target structure.
It is therefore beneficial to be able to provide demolition equipment that can continuously operate through discrete sequences of respective shearing and/or pulverizing steps and subsequent picking, placement and removal steps, without the need to reconfigure, reassemble or re-mount respective tool heads or the like.
Other arrangements in the prior art provide permanent magnets incorporated into boom arms, such as those described in U.S. Pat. Nos. 5,628,611 and 6,015,108, also hereby incorporated herein by reference. However, these references do not allow the advantage of readily moving the magnet into an effective position where the shearing occurs and metal scrap is released, without interference from portions of the shearing or pulverizing tool.
Accordingly, there remains a need for demolition equipment and methods able to address the concomitant problems of the need for high performance cutting and pulverizing tools within a complex and variable demolition site landscape, to be able to increase the efficiency in demolition site clean-up in terms of the amount of scrap material that can be processed and removed from a demolition site per unit time, as well as to provide lower operational costs.
In this regard, there also remains a need for combination shearing and magnetic lifting tools that more effectively allow the operator to alternatively deploy and store both the shearing or pulverizing tool into an effective position where the shearing occurs and metal scrap is released, without interference from portions of the shearing or pulverizing tool that may hinder the operator's natural and coordinated use of both the shearing or pulverizing tool and the lifting magnet.